The technique of Nuclear Magnetic Resonance spectroscopy is being applied to the study of the antibiotic Lasalocid A (X537A) and its binding to Serotonin and several cations to examine its function in membrane transport. The structure of compound 48/80 is being investigated by incorporation of enriched Carbon-13 paraformaldehyde. BIBLIOGRAPHIC REFERENCES: Highet, R.J., Perold, G.W., and Sokoloski, E.A. Characterization of spiro-bislactonic phenolic metabolites of proteaceae by Carbon-13 nuclear magnetic resonance. J. Org. Chem., 41: 3860, 1976. Shukla, Y.N., Sokoloski, E.A., Fales, H. M., and Kapadia, G.J. 6-Methoxy-7, 8-Methylenedioxycoumarin from Melochia tomentosa. Phytochemistry 15: 1788, 1976.